The objective of the Hazard Identification Core is to provide toxicological and analytical services that will be utilized by virtually all of our Biomedical and Environmental Sciences Research Projects. This Core provides a number of services that many investigators require and that some investigators need, but are not technologically equipped to perform. The Specific Aims of this Core are to provide research support in two areas: Biological Response and Metal Analysis. The Biological Response section will include ecotoxicity (bacterial and daphnia), mammalian cytotoxicity (HepG2 cells), and genotoxicity (Ames) assays. The daphnia - ecotoxicity analyses will be performed in a consortium agreement with the Dartmouth SBRP. The Metal Analyses section will use ICP-Mass Spectrometer analysis for total metal content and HPLC-ICP-MS for analysis of chemical species of metal. Multiple metals will be analyzed but the majority of the analyses will be for arsenic and its chemical species (e.g. metabolites). The Hazard Identification Core efficiently provides common analyses (biological or metal analyses) to our SBRP investigators thus allowing for more SBRP funds to be directed to the individual research projects as well as uniform quality control of the analyses.